Implant delivery system and implants

ABSTRACT

The invention generally relates to devices and methods that provide for guided delivery of a heart replacement valve or other implant into the vasculature. In certain embodiments, a delivery device of the invention includes an outer sheath and an inner sheath moveably disposed within the outer sheath. The outer sheath includes a first imaging element and defining a center lumen that leads to an opening. The outer sheath is further configured to releasably hold an implant within the center lumen. The first imaging element is configured to at least partially surround the center lumen such that the implant is deployable through the first imaging element. The inner sheath is configured to engage with and deploy the implant out of the opening of the elongate body and into a body lumen.

RELATED APPLICATIONS

This application is a continuation-in-part of U.S. Nonprovisional Ser.No. 14/134,324, filed Dec. 19, 2013, which claims the benefit of andpriority to U.S. Provisional Ser. No. 61/740,196, filed on Dec. 20,2012, and U.S. Provisional Ser. No. 61/777,619, filed Mar. 12, 2013. Theentirety of each application is incorporated by reference herein.

TECHNICAL FIELD

The present invention generally relates to an apparatus and method forguided delivery of replacement heart valves, such as valve stents, intothe vasculature.

BACKGROUND

Heart valves help regulate blood flow through the heart chambers, theleft and right atria and the left and right ventricles, each of whichincludes its own one-way exit valve. These valves are identified as theaortic, mitral (or bicuspid), tricuspid and pulmonary valves. Whenfunctioning normally, the valves maintain one-way blood flow through theheart during each heartbeat and prevent backflow.

When a valve malfunctions or is diseased, it may constrict the volume ofblood allowed through the valve or permit blood to flow back within theheart. Constriction (known as stenosis) is the abnormal narrowing of avalve due to, e.g., a build of calcium deposits, tissue, or scarring.Backflow (known as insufficiency or regurgitation) occurs when the valvestructure is torn, loose, stretched, or thin. Several factors may causevalve stenosis and/or insufficiency such as congenital valve disease,infection, and injury.

Constriction and/or backflow require the heart to work harder in orderto supply adequate blood throughout the body. Left untreated, abnormalblood flow associated with malfunctioning or diseased valves can haveserious side effects, such as shortness of breath, heart attack, stroke,and even death. In light of the serious side effects, heart valvereplacement surgery is often indicated to correct the disruption ofblood flow from the heart.

Heart valve replacement surgery introduces a valve implant (i.e. valvestent) to replace the dysfunctional native valve. Conventional heartvalve replacement surgery is a highly invasive, open-heart procedureconducted through the patient's sternum. More recently, percutaneousheart valve replacement procedures have emerged as a safer,less-invasive alternative to open-heart surgery. These less-invasiveprocedures typically involve introducing a delivery catheter underfluoroscopic guidance to deliver a replacement valve implant. While lessinvasive, the fluoroscopic guidance alone prevents precise placement ofthe implant with the catheter and does not provide intraluminalassessment of the valve before, during, and after the valve replacementsurgery.

SUMMARY

The present invention utilizes a single catheter device withintravascular imaging and/or functional flow sensing capabilities toguide and facilitate valve replacement surgery. Devices and methods ofthe invention can be used to verify a location of a diseased valve,assess the condition of the diseased valve, visualize implantation ofthe replacement valve within the heart, assess placement of the deployedreplacement valve, and evaluate restoration of blood flow afterreplacement. With the enhanced guidance provided by the present cathetersystems, the risk of unnecessarily injuring the heart or surroundingvasculature tissue due to improper deployment/placement of a valve stentor other implant is minimized. Because systems of the invention requireonly one catheter for pre-implantation assessment, valve implantation,and post-implantation assessment, the number of catheters that areintroduced into the vasculature is minimized. This reduces the riskassociated with exchanging and moving multiple catheters within thedelicate vasculature that may already be weakened by disease.

Aspects of the invention are accomplished with a device for deliveringan implant (such as a valve stent) that includes an imaging elementand/or one or more functional flow sensors. In certain embodiments, thedelivery device includes an outer sheath defining a center lumen thatleads to a distal opening. An implant can be releasably held within thecenter lumen or driven through the center lumen. The outer sheath alsoincludes an imaging element configured to at least partially surroundthe center lumen such that the implant is deployable through the firstimaging element. Because the implant passes through the first imagingelement and then deploys into the body lumen, the first imaging elementdoes interfere with implant deployment. Moreover, this configurationprovides a small profile because the implant and first imaging elementare concentrically aligned. The imaging element can be used to obtainintraluminal images of the vasculature to assess the condition of thediseased valve, determine the appropriate placement of the catheter forvalve delivery, and assess placement of the valve stent as deployedwithin the heart.

For deployment of the implant, the delivery device of the inventionincludes an inner member disposed within the outer sheath's center lumensuch that movement of the inner member relative to the outer sheath (orvice versa) deploys an implant from the distal opening of the outersheath. The inner member may be a push rod or an inner catheter sheath.In certain embodiments, the inner member is used to push the implant sothat the implant deploys out of the center lumen. Alternatively, theinner member can be used to maintain the positioning of the implantrelative to the outer sheath (or elongate body) such that proximalmovement of the outer sheath deploys the implant out of the device andinto the implantation site.

The implant delivery device may also include one or more sensors incombination with the first imaging element. The one or more sensors maybe used to obtain functional flow measurements, and may include apressure sensor, flow sensor, temperature sensor or any combinationthereof. A benefit of pressure/flow sensors is that one is able toobtain functional flow measurements of the vasculature. Functional flowmeasurements can be used to assess the health of the valve andcirculation prior to implantation and/or assess blood flow andcirculation after placement of the implant in order to confirm properdeployment. Preferably, the one or more sensors are located near adistal end of the implant delivery device, and in close proximity to theopening through which the implant is deployed. The one or more sensorscan be located near or embedded within the imaging element of theimplant delivery device.

The outer catheter sheath (i.e. elongate body) of the delivery systemmay include one or more radiopaque markers along the length of thecatheter sheath. The radiopaque markers allow one to determine thepositioning of the catheter relative to the vasculature when viewed withan external imaging modality (such as fluoroscopy). This further aids indetermining whether the catheter is appropriately placed forimplantation of, e.g., a replacement valve.

Certain aspects of the invention provide that the inner member (e.g.push rod or inner sheath) includes a second imaging element. After theimplant is deployed into a lumen (such as a heart valve) and engagedwith the luminal wall, the inner member may enter the lumen and itsimaging element may be used to image the implant as implanted. Aparticular benefit of this aspect is that the second imaging element canimage the implant as engaged with the luminal wall without touching orinterfering with the implant because the inner member has a smallerprofile than the elongate body and is able to fit within a cavity formedby the deployed implant (such as a valve or a filter). For example, ifthe implant is filter, the filter legs expand from a center point andengage with the vessel walls, thereby creating a funnel-like cavitybetween the filter legs. The inner member may move within thefunnel-like cavity between the expanded wire legs to image the legs asengaged with the vessel wall.

Devices of the present invention may be used in a variety of bodylumens, including but not limited to intravascular lumens such as heartchambers and coronary arteries. Typically, devices of the invention areused to a) deploy valve implants to replace diseased/damaged nativevalves of the heart or b) to deploy filter implants within thevasculature to prevent thrombi from travelling within the bloodstream.However, devices of the invention can be used to delivery other implantsfor a variety of reasons. For example, the implant may be introducedinto a vessel to occlude the vessel downstream and eliminate blood flowwithin the vessel. In another example, the implant may be introducedinto a vessel to provide open mechanical support to a diseased vessel.Suitable implants for delivery into a body lumen include, but are notlimited to a plug, a stent, a pH sensor, a pressure monitor, a plug, afilter, or a valve. The implant may be expandable, such asself-expandable valve stents or filters.

In certain aspect, an implant delivery device of the invention includesan outer catheter sheath and an inner catheter sheath. The outercatheter sheath includes a first imaging element and defines a centerlumen that leads to an opening. The outer catheter sheath is configuredto releasably hold an implant within the center lumen or receive theinner catheter sheath engaged with an implant within the center lumen.The first imaging element is configured to at least partially surroundthe center lumen such that the implant is deployable through the firstimaging element. The inner catheter sheath is moveably disposable withinthe center lumen of the outer catheter sheath. Movement of the innercatheter sheath or outer catheter sheath relative to each other deploysthe implant into a desired implantation site.

The first imaging element may be positioned on or formed as part of anouter surface of a distal end of the outer catheter sheath. In certainembodiments, the first imaging element surrounds the distal end of theouter catheter sheath at a position slightly proximal (e.g. twomillimeters or less) to the opening of center lumen. With thisarrangement, the operator is able to locate an implantation site withthe first imaging element, and then position outer catheter sheath forimplant deployment such that the opening is slightly proximal to thelocated implantation site. In this manner, the operator can know thatthe implant is being delivered at a location slightly distal toreal-time images being obtained from the first imaging element.

In order to facilitate deployment of the implant out of the center lumenand into a body lumen, the inner catheter sheath can include a pushelement configured to engage with the implant. For example, the pushelement of the inner catheter sheath may include a substantially flatsurface that is substantially flush with the wall of the center lumen.The push element may form the distal end of the inner catheter sheath.In certain embodiments, the inner catheter sheath further includes asecond imaging element. The second imaging element may be proximal tothe push element of the inner catheter sheath. The second imagingelement can be used to obtain images of the luminal surface when atleast a portion of the inner catheter sheath is deployed out of theopening of the center lumen. In this manner, the second imaging elementallows one to obtain images of the implant as implanted within the bodylumen.

Aspects of the invention further include methods for delivery an implantinto a body lumen. According to some embodiments, the method includesintroducing an implant delivery device into a body lumen. The implantdelivery device includes an elongate body with a first imaging elementand a center lumen that leads to an opening. The first imaging elementis configured to at least partially surround the center lumen. Thedevice further includes an implant releasably held within the centerlumen and an inner member (such as a push rod or inner catheter sheath)being moveably disposed within the center lumen. The method furtherincludes imaging a surface of the first imaging element to locate animplantation site, positioning the elongate body for deployment of theimplant based on the imaging step, and deploying the implant out of theopening and into the implantation site.

The first and second imaging elements can be a component of any knownintraluminal imaging apparatus. Suitable imaging apparatus for use withthe implant delivery device of the invention include, for example,optical-acoustic sensor apparatuses, intravascular ultrasound (IVUS) oroptical coherence tomography (OCT).

Other and further aspects and features of the invention will be evidencefrom the following detailed description and accompanying drawings, whichare intended to illustrate, not limit, the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts a distal end of an implant delivery device according toone embodiment.

FIG. 2 shows an implant delivery device according to certainembodiments.

FIG. 3 depicts a longitudinal cross-section of a distal portion of thedelivery device according to certain embodiments.

FIG. 4 depicts another cross-section along the x-axis of a distalportion of the delivery device according to certain embodiments.

FIG. 5 depicts an alternative embodiment of the delivery device.

FIGS. 6-11 illustrate an exemplary delivery device of the invention inoperation.

FIG. 12A-12C depicts filters according to certain embodiments.

FIG. 13 is a system diagram according to certain embodiments.

FIGS. 14A-C depict an alternative embodiment of the delivery device.

DETAILED DESCRIPTION

The present invention generally relates to intraluminal systems withcombined implant delivery and imaging capabilities. The delivery systemsof the invention provide for 1) real-time imaging of intraluminalsurfaces to detect/evaluate a location of interest (e.g. implantationsite); 2) real-time monitoring of functional flow parameters (e.g.pressure/flow) within the vasculature to detect/evaluate the location ofinterest; 3) delivery of an implant into the implantation site; 4)real-time imaging of the implant as engaged with the intraluminalsurface without interfering with the implant as implanted; and 5)real-time monitoring of functional flow parameters within thevasculature after implantation to evaluate blood flow and circulation.

Because the above features are accomplished with one system introducedinto a body lumen, this present invention eliminates the need tointroduce multiple catheters into the body. For example, there is noneed to introduce and remove an imaging or sensor catheter to locate aregion of interest, then introduce and remove a delivery catheter todeliver an implant, and then re-introduce the imaging or sensor catheterto evaluate the implant as implanted.

In certain embodiments, systems and methods of the invention image anddeliver an implant within a lumen of tissue. Various lumen of biologicalstructures may be imaged and receive an implant including, but notlimited to, blood vessels, vasculature of the lymphatic and nervoussystems, various structures of the gastrointestinal tract includinglumen of the small intestine, large intestine, stomach, esophagus,colon, pancreatic duct, bile duct, hepatic duct, lumen of thereproductive tract including the vas deferens, uterus and fallopiantubes, structures of the urinary tract including urinary collectingducts, renal tubules, ureter, and bladder, and structures of the headand neck and pulmonary system including sinuses, parotid, trachea,bronchi, and lungs.

The delivery system may be used to deliver any suitable implant into abody lumen. Suitable implants for delivery into the lumen include astent, a plug, a pH sensor, pressure monitor, a plug, a filter, or avalve. The delivery system may be used to deliver an implant for avariety of reasons. For example, the implant may be introduced into avessel to occlude the vessel downstream to eliminate blood flow withinthe vessel. In another example, the implant may be introduced into avessel to provide open mechanical support to a diseased vessel. In yetanother example, delivery devices are well suited to deliver areplacement valve (such as a valve stent) into the heart to replace adamaged or diseased valve. The implant used for purposes of describingthe components and function of the delivery system depicted in FIGS.1-11 is a filter.

In particular embodiments and as discussed in reference to FIGS. 1-11,the delivery system of the invention can be used to deploy a filter intovessel of the vasculature to block thrombi from traveling through theblood stream. (Although it is understood that other implants (such asvalve stents) can be delivered in the same or similar manner.) Thesetypes of filters are typically introduced into the inferior vena cavavein to block thrombi originating in the lower extremities from breakingoff and traveling through the bloodstream. Prior to filter placement,the surgeon must take care to locate the proper filter location. Theoptimal location for filter placement is in the infrarenal inferior venacava with the apex of the filter just below the level of the lowestrenal vein because, at this level, a thrombus caught by the filter willbe exposed to renal vein blood flow, which may promote dissolution bythe intrinsic lytic system. In order to determine appropriate placementof a vena cava filter, a surgeon must take care to avoid encroachment onthe renal veins and to ascertain the absence or presence of thrombuswithin the vena cava. For example, a filter placed at or above the renalveins can lead to renal vein thrombosis and deterioration of renalfunction if the filter, and thus the vessel, become occluded. Inaddition, the filter should not be placed on a thrombus tissue, butrather should be placed on healthy vessel walls to ensure the filterengages with the wall of the vena cava.

The delivery system of the invention may optionally involve theintroduction of an introducer sheath. Introducer sheaths are known inthe art. Introducer sheaths are advanced over the guidewire into thevessel. A catheter or other device may then be advanced through a lumenof the introducer sheath and over the guidewire into a position forperforming a medical procedure. Thus, the introducer sheath mayfacilitate introducing the catheter into the vessel, while minimizingtrauma to the vessel wall and/or minimizing blood loss during aprocedure.

FIG. 1 depicts the distal portion 50 of a delivery system 100 accordingto certain embodiments. The delivery system 100 includes an elongatebody 25 and an imaging element 10 located near a distal tip 15 of theelongate body 25. An opening (not shown in FIG. 1) is open in the distaldirection on the distal tip 15, through which an implant can bedelivered into a body lumen. The imaging element 10 is a distance L fromthe distal tip 15. In certain embodiments, the imaging element ispositioned 2 millimeters or less from the distal tip 15. Ideally, theimaging element 10 is positioned as close as possible to the distal tip15 to minimize the distance between the actual location of the imagingand an implant delivery site. The imaging element 10 can partially orfully surround the elongate body 25. In addition, the imaging element 10can be positioned on or formed as part of an outer surface of the distalend 50 of the elongate body 25. In preferred embodiments, the imagingelement 10 surrounds the elongate body 25 to provide cross-sectionalimaging of the body lumen (i.e. to provide a 360 degree slice of thevessel at different longitudinal sections of the body lumen). If theimaging element 10 only partially surrounds the elongate body 25, theelongate body 25 could be configured to rotate to providecross-sectional imaging.

In certain aspects, delivery systems 100 of the invention include one ormore sensor elements 12 in combination with one or more imaging elements10. The one or more sensor elements 12 may include a pressure sensor,flow sensor, temperature sensor, or any combination thereof. Sensorelements 12 and methods of using information obtained from sensorelements 12 are described in more detail hereinafter.

FIG. 2 further depicts a delivery device 100 of the invention accordingto certain embodiments. The delivery device 100 is shown coupled to aconnector. Connector fitting 35 is attached at a proximal portion 55 ofthe elongate body 25. Connector fitting 35 provides a functional accessport at the proximal end of devices of the invention. For example, aninner member 70 (not shown in FIG. 2) or delivery sheath can betelescoped through the elongate body 25 through the connector fitting35. Through the connector fitting 35 and via cable 26, the imagingelement 10 and/or one or more sensors 12 elongate body 25 are operablycoupled to an operating system 40. In addition, a proximal end 71 of theinner member 70 be coupled to the operating system 40. (The inner member70 is shown within the center lumen of the elongate body in FIG. 3.) Itis also understood that cable 26 and proximal end 71 can be routedthrough either port of the connector fitting 35. Typically, theoperating system 40 provides a means to transmit electricity and receivedata from imaging elements 10 and sensors 12 of the delivery systems.The operating system 40 can be a component of computerized ultrasoundassembly equipment, optical coherence tomography assembly equipment,functional flow equipment or equipment of another imaging/sensor system.Various imaging assemblies and sensor assemblies suitable for use withdevices of the invention are described in more detail hereinafter.

In addition, the operating system 40 can be configured to provide acontrolled translation of the inner member with respect to the elongatebody 25. As alternative to one operating system, the elongate body 25and the inner member 70 can be coupled to separate operating systems.

Referring back to FIG. 2, the elongate body 25 of the delivery device100 may further include one or more radiopaque markers 28 located alongthe length of the elongate body 25. The radiopaque markers 28, when usedin conjunction with an external imaging modality such as an angiogram,indicate the positioning of the catheter as disposed within a subject.The radiopaque markers 28 may be formed from a radiopaque object or aradiopaque ink. In certain embodiments, the radiopaque markers 28 arespaced a certain distance apart in order to allow a quick assessment asto the relative position of the elongate body 25 within the vasculature.The spatially-separated radiopaque markers 28 may indicate when thedevice is a certain distance within a particular vessel of interest. Forexample, the radiopaque markers 28 may indicate when the device is 25 cminside the femoral vein, which is an ideal distance within the vein toplace an implant such as a valve stent.

FIG. 2 also shows a guidewire opening 30 near the distal portion 50 ofthe elongate body 25. As shown in FIG. 2, the delivery system 100 is arapid exchange catheter device. However, the delivery system 100 can bedesigned as an over-the-wire system or a rapid exchange system.Over-the-wire catheters include a guidewire lumen that runs the fulllength of the catheter (and is often the same as a catheter's centerlumen). Rapid exchange catheters include a guidewire lumen extendingonly through a distal portion of the catheter. With respect to theremaining proximal portion of the catheter, the guidewire exits theinternal catheter lumen through a guidewire opening 30, and theguidewire extends in parallel along the proximal catheter portion.Delivery systems of the invention that include an over-the-wireconfiguration are depicted in FIGS. 14A-14C.

FIG. 3 depicts a cross-section of the distal portion 50 of the deliverydevice 100 shown in FIG. 1 according to certain embodiments. Thedelivery device 100 includes an elongate body 25 that defines a centerlumen 115. The center lumen 115 extends to an opening 20 through whichan implant can be deployed. The elongate body 25 includes an imagingelement 10 positioned on or formed as part of the outer surface of theelongate body 25. In addition, the elongate body 25 includes one or moresensors 12 positioned on or formed as part of the outer surface of theelongate body 25. The imaging element 10 is a component of an imagingassembly, and the one or more sensors 12 may be a component of a sensorassembly, which are described in more detail hereinafter. The imagingelement 10 and sensor 12 of the elongate body can be connected totransmission line(s) 60. The transmission line(s) 60 are configured totransmit electricity to the imaging element 10 and sensors 12 andreceive imaging/sensor signals from the imaging element 10 and sensors12. The transmission(s) line 60 is disposed through a transmission lumen65 of the elongate body. The transmission line(s) 60 can include one ormore signal lines, e.g. one or more signal lines specific to the imagingelement 10 and one or more single lines specific to the sensor 12.

An inner member 70 is disposed within the center lumen 115 of elongatebody 25. The inner member 70 is movable within the center lumen 115 andcan translate with respect to the elongate body 25 in the forward(distal) and backward (proximal) directions, as indicated by arrow x. Inaddition, the elongate body 25 can translate and move relative to theinner member 70. In certain embodiments, the inner member 70 is moveddistally within the center lumen 115 to engage the inner member 70 witha filter 95 and to push the filter 95 into a body lumen. The innermember 70 may be a push rod or an inner catheter sheath.

According to certain embodiments, the inner member 70 includes a pushmember 120 located at a distal end of the inner member 70. The pushmember 120 engages with a proximal end of the filter 95 (or otherimplant). As shown in FIG. 3, the push member 120 engages with thehooked ends 125 of the filter legs 105. The push member 120 can be aflat or slightly-cupped shaped surface (as shown) and can extend thewidth of the center lumen. The slightly-cupped shaped surface of thepush member 120 acts to contain the legs and minimize the hooks ends 125from engaging with the surface 117 of the center lumen 115. In addition,the push-member can be shaped to specially mate with the filter beingdeployed. In certain embodiments, the surface 117 of the center lumen115 that is exposed to the filter hooks ends 125 is formed of a materialthat prevents the hook ends 125 from perforating, penetrating, orcatching on the surface 117 of the center lumen 115 during deployment ofthe filter 95.

In certain embodiments and as shown, the inner member 70 includes acenter member imaging element 90. The center member imaging element 90is a component of an imaging assembly, which are described in moredetail hereinafter. The center member imaging element 90 is proximal tothe push member 120. Preferably, the distance between the center memberimaging element 90 and the push member 120 is minimized so that theimaging element 90 substantially images from a distal end of the innermember 70. Like the imaging element 10 of the elongate body 25, theimaging element 90 of the inner member 70 can surround the inner memberto provide for cross-sectional imaging (360 degree) of the body lumen.If the center member imaging element 90 only partially surrounds theinner member 70, the inner member 70 could be configured to rotate toprovide cross-sectional imaging. The center member imaging element 90 isconnected to a transmission line 80, which transmits electricity to thecenter member imaging element 90 and receives imaging signals from theimaging element 90. The transmission line 80 can include one or moresignal lines. The transmission line 80 can be disposed within a lumen 85of the inner member 70. Alternatively, the transmission line 80 can beintegrated into the body of the inner member 70. FIG. 5 depicts analternative embodiment of the delivery device in which the inner member70 does not include a center member imaging element.

The elongate body 25 further includes a rapid exchange guidewire lumen33. The guidewire lumen has a guidewire opening 30 at a proximal end anda guidewire opening 31 at a distal end. The elongate body 25 can beguided over a guidewire (not shown) extending through the guidewirelumen 33. During implant deployment, the guidewire can be retracted intothe guidewire lumen 33 to prevent the guidewire from interfering withthe implant 95 as it is being deployment. Alternatively, the deliverydevice 100 can be configured as an over-the-wire device.

The elongate body 25 is also configured to releasably hold an implant,such as the filter 95 as shown. The filter 95 includes a plurality oflegs 105 connected to a center hub 110. The filter legs 105 areconfigured to expand radially to engage with a surface of a body lumenwhen fully deployed. As shown in FIG. 3, the filter legs 105 are in acontracted state. FIGS. 9 and 12 a depict a filter 95 in its fullyexpanded state. The filter 95 includes a plurality of legs 150 with hookends 125. The hook ends 125 secure the filter 95 into the body lumen.The plurality of legs 105 forms a funnel-like cavity 130 between thelegs 105. As discussed more fully hereinafter, the inner member 70 canmove within the funnel-like cavity 130 of an implanted filter 95 toobtain images of the filter as implanted. In addition and as shown inFIG. 12A, a filter 95 can include capture members 135 that act tofurther prevent a thrombus from passing through the filter. In additionto the filter 95 shown, most commercially available filters can be usedwith the delivery device of the invention. Suitable filters aredescribed in U.S. Pat. Nos. 6,468,290, 7,534,251, and 7,972,353.

FIGS. 12B-12C illustrate other filters suitable for use in devices andmethods of the invention. FIG. 12B illustrates a caged filter 200 thatincludes a mesh, collapsible cage body disposed between end portions201. The end portions 201 define a lumen so that the cage filter may beridden over a guidewire. FIG. 12C depicts a winged-filter 208 disposedwithin a vessel. The winged-filter 208 includes an expandable two-partframe with a mesh portion 206 disposed within at least one part of theframe.

Each of the filters illustrated in FIGS. 12A-12C are configured toexpand to securely-fit against the vessel wall. This allows the filtersto capture/snare blood clots traveling through the vasculature withoutrisk of dislocating the filters.

Typically, a filter implanted within a blood vessel is retrieved fromthe vessel after a certain period of time. There are often severalissues associated with the retrieval that can lead to damage to thepatient's vessel or result in leaving the filter within the patientpermanently, which could deteriorate the vessel wall. In order toovercome the issues associated with retrieval of filters and filtersleft in the body permanently, certain embodiments of the inventionprovide filters with bioabsorable properties that decay over time andeventually absorb into the body's blood stream and/or tissue. A filterof the invention may be made with any material having bioabsorableproperties, such as magnesium alloys and bioabsorbable polymers.Specifically, bioabsorbable material may include, for example, magnesiumalloys, polyglycolic acid, polygalctin 910, poliglecaprone,polydioxanone, poly-a-hydroxy acids, e.g. polylactides, polyglycolidesand their copolymers, polyanhydrides, polyorthoesters, segmented blockcopolymers of polyethylene glycol and poly terephthalate, tyrosinederivative polymers or poly(ester amides). Filters having one or morecomponents may be formed from the same or different bioabsorablematerials.

In certain embodiments, the elongate body can include radiopaque markerson the distal tip 15 and the imaging element 10 to assist in determiningthe location of the elongate body in the vasculature relative to theimages obtained by the imaging element. This will allow an operator tovisualize the location of the delivery device within the vasculature viaan angiogram. The imaging obtained by imaging element 10 may beco-located with the radiopaque markers as described in co-assigned andco-pending application entitled, “LOCATING INTRAVASCULAR IMAGES”.

FIG. 4 depicts a cross-section along the y-axis of the elongate body 25shown in FIG. 3. FIG. 4 illustrates the lumens of elongate body 25. Asdiscussed, the elongate body 25 includes center lumen 115, transmissionlumen 65, and a guidewire lumen 33. The transmission lumen 65 does nothave to fully surround a portion of the elongate body 25.

FIGS. 6-11 illustrate the delivery device illustrated in FIG. 3 inoperation. FIG. 6 shows the delivery device 100 disposed within a lumen185 of vessel 180. The delivery device can be introduced in to a vesselusing methods known in the art. Typically, a guidewire is inserted intothe vessel using the Seldinger technique and the delivery device isguided over the guidewire to the vessel and region of interest. Once thedelivery device 100 is inserted, the operator can obtain real-timeimages of the luminal surface of the vessel using imaging element. Usingthe real-time imaging of the luminal surface of the vessel 185, theoperator is able to locate a target implantation site, such as targetimplantation site 190. In certain embodiments, the one or more sensors12 are used to measure functional flow parameters within the vessel toassist in identifying an implantation site. For example, the one or moresensors 12 can indicate areas of low or high blood pressure within avessel.

After the target implantation site 190 is located, the operator placesthe distal tip 15 of the delivery device proximal to the targetimplantation site 190 (as shown in FIG. 7). A user interface module(included in operating systems 40) shown in FIG. 1) connected to theimaging element 10 and the elongate body 25 can assist the operator indetermining the amount of pull back of the elongate body 25 required sothat the distal tip 15 is located proximal to the implantation site 190located by the imaging element 10.

Once the elongate body 25 is positioned for deployment, the inner member70 is moved distally through the center lumen 115 of the elongate body25 to push the filter 95 out of the opening 20 of the distal tip 15. Asshown, the push member 120 of the inner member 70 engages with thefilter legs 105 to deploy the filter 95 into the vessel lumen 185towards the implantation site 190. Once the proximal ends 125 of thefilter legs 105 exit into the vessel lumen 185 from the opening 20, thelegs 105 spring open and attach themselves via the hook ends to thevessel wall 180. To assist with expansion of the filter legs 105, theinner member 70 can be retracted back into the center lumen 115 and awayfrom the filter legs 105. FIG. 8 shows the filter 95 as implanted withinthe vessel 180 with the inner member 80 retracted back into the elongatebody 25.

When the filter is placed in the vessel, the inner member 70 can bedeployed out of the opening 20 and into the vessel lumen 185 to providereal-time images of the filter 95 as engaged with the vessel wall 180.As shown in FIG. 9, the inner member 70 is deployed into the opening andinto the funnel-like cavity 30 formed between the plurality of filterlegs 95. The imaging element 90 of the inner member 70 can obtainreal-time images to evaluate and ensure that the filter leg hook ends125 of the filter 95 are properly attached to the wall of the vessel180. FIG. 10 shows a cross-section of the vessel 180 with the imagingelement 90 of the inner member 70 disposed between the hook ends 125 offilter legs 105 engaged with the wall of the vessel 180. After visualconfirmation of the implanted filter 95, the inner member 70 isretracted back into the center lumen 115 of the elongate body 25, andthe delivery device 100 can be removed from the vessel lumen 185 (asshown in FIG. 11). In certain embodiments, the one or more sensors 12are used to assess functional flow parameters within the vessel in orderto assess the success of the implantation, e.g. whether blood is flowingthrough the implant properly.

FIGS. 14A-14C illustrate another embodiment of the delivery device 100.In this embodiment, the delivery device 100 is a duel sheath system(that delivers an implant using an outer sheath 1102 and an inner sheath1103). The delivery device 100 of FIGS. 14A-14C may be used to deliveryany type of implant, such as a filter, valve, etc.

As shown in FIG. 14A, the delivery device 100 includes an outer sheath1102 that is coupled to a connector fitting 1135 (similar to connectorfitting 35) at a proximal end. The outer sheath 1102 is an elongate body(such as elongate body 25) that defines a lumen configured to receive aninner delivery sheath 1103 (as shown in FIGS. 14A-14C). The connectorfitting 1135 allows transmission lines of an imaging element 10 and/orone or more sensors 12 to connect to an operating system 40 (such asshown in FIG. 2). The outer sheath 1102 may include an imaging element10 and one or more sensors 12 at a distal portion of the outer sheath1102. The imaging element 10 and the one or more sensors 12 may have thesame configuration on the outer sheath 1102 as it does on the elongatebody 25 of the embodiment depicted in FIGS. 1-3. The distal end of theouter sheath 1102 defines an opening 1150 through which an implant 1104may be delivered.

The outer sheath 1102, like the elongate body 25, may include one ormore radiopaque markers 1128. The radiopaque markers 28, when used inconjunction with an external imaging modality such as an angiogram,indicate the positioning of the catheter disposed within a subject. Theradiopaque markers 28 may be formed from a radiopaque object or aradiopaque ink. In certain embodiments, the radiopaque markers 28 arespaced a certain distance apart in order to allow easier assessment asto the relative position of the elongate body 25 within the vasculature.The spatially-separated radiopaque markers 28 may indicate when thedevice is a certain distance within a particular vessel of interest. Forexample, the radiopaque markers 28 may indicate when the device is 25 cminside the femoral vein, which is an ideal distance within the vein toplace an implant such as a valve stent.

For implant delivery using the device shown in FIGS. 14A-14C, theimplant is deployed by translating the outer sheath 1102 with respect toan inner sheath 1103. The inner sheath 1103 for deploying the implantcan be introduced into the outer sheath 1102 through a port 1140 of theconnector fitting 1135. The outer sheath 1102 may be positioned withinthe vasculature prior to introduction of the inner sheath 1103 into theouter sheath 1102. In this embodiment, the inner sheath 1103 can be usedto drive an implant 1104 through the outer sheath 1102. Alternatively,the inner sheath 1103 may be pre-disposed within a lumen of the outersheath 1102 and then both sheaths may be introduced concurrently intothe vasculature. In this embodiment, an implant may be disposed within adistal portion of the outer sheath 1103 and positioned on or against adistal end of the inner sheath 1103 also disposed within the outersheath 1103.

The duel-sheath delivery system depicted in FIGS. 14A-14C may be guidedto a location of interest within the vasculature using a guidewire. Asshown in FIGS. 14A-14C, the system 100 has an over-the-wireconfiguration, in which the system may be ridden over a guidewire placedin the distal opening 1150 of the outer sheath 1103. The implant 1104and inner sheath 1103 are likewise configured to receive a guidewire.For example, the implant defines an opening or space through which theguidewire can be retracted past the deployed implant and out of thebody.

FIGS. 14B and 14C depict deployment of an implant using the duel-sheathdelivery device 100. As shown in FIG. 14B, the inner sheath 1103 andimplant 1104 disposed within the distal portion 50 of the outer sheath1102. Prior to deployment, the imaging element 10 and/or the one or moresensors 12 can be used to determine the desired location within thevasculature for implant deployment. The radiopaque markers 1128 may alsobe used in conjunction with the imaging element 10 and sensors 12 todetermine the desired implantation location.

In the un-deployed state (FIG. 14B), an implant 1104 (such as implant95, 200, 204) is disposed within the lumen 1105 of the outer sheath 1102and rests against the distal end of the inner sheath 1102. Fordeployment, the outer sheath 1102 translates proximally with respect tothe inner sheath 1103 as shown in FIG. 14C. Due to the proximaltranslation of the outer sheath 1102, the implant 1104 is deployedthrough the opening 1150 and into the vessel. Alternatively, the innersheath 1102 may translate distally relative to the outer sheath 1103 todeploy the implant.

In addition to delivery filter implants as described above, devices ofthe invention (e.g. depicted in FIGS. 1-3 and 14A-14C) can also bebeneficially used to deliver valve stents. Valve stents are often usedto replace a diseased valve (e.g. a heart valve) that no longer opensand closes properly. Heart valves help manage blood flow through theheart chamber, the left and right atria and the left and rightventricles, each of which includes its own one-way valve. The naturalheart valves are identified as the aortic, mitral (or bicuspid),tricuspid and pulmonary valves. Prosthetic heart valves can be used toreplace any of these naturally occurring valves, although repair orreplacement of the aortic or mitral valves is most common because theyreside in the left side of the heart where pressures are the greatest.Devices of the invention can be used to a) determine whether replacementof a heart valve is necessary (i.e. assess whether the natural valve isdiseased or damage), b) delivery an replacement implant valve and c)assess the success and function of the implant valve after implantation.

Diseased or damaged valves may include heart valves that do not openfully due to calcium deposits or scarring, which both attribute to acondition known as stenosis. Valve stenosis is known as an abnormalconstriction of a heart valve, which causes less blood to flow throughthe chamber and onward to the rest of one's body. A damaged valve mayalso cause a condition known as insufficiency or regurgitation. Valveinsufficiency is the leaking of blood through a valve due to aninability of a valve to close tightly. Leakage through a valve generallycauses a heart to operate less efficiently, as the heart must workharder to maintain a proper amount of blood flow there through. Valveinsufficiency may be caused by torn, loose, or thin valve tissue. Valveinsufficiency and stenosis are both associated with abnormal changes inblood flow and pressure within the heart.

An advantage of devices 100 of the invention is that the imaging element10 and the one or more sensors 12 can be used to indicate whetherstenosis or valve insufficiency is present. For example, calciumdeposits and scarring that lead to stenosis can be visually indicated,and changes in blood pressure and flow can be assessed using the one ormore sensors. If there is abnormal blood flow or pressure, the valve maysuffer from stenosis or have damaged tissue. In some circumstances,lower than normal blood flow and pressure is associated with stenosisand/or valve insufficiency. Pressure and flow sensors 12 suitable foruse with devices of the invention to determine whether blood flowthrough a valve is abnormal are described in more detail hereinafter. Inaddition, imaging elements 10 suitable for use with devices of theinvention to assess diseased or damaged valves are described in moredetail hereinafter.

Replacement valves for implantation are known in the art and come inseveral different varieties. Suitable replacement valves that can beimplanted using devices of the invention include, for example,replacement valves with an expandable frame and one or more valveleaflets disposed within the expandable frame. Specific examples ofvalves that may be implanted using devices of the invention include, forexample, the Lotus valve (Boston Scientific Inc., MN USA), Centera valve(Edward Lifesciences Inc., CA USA), Portico valve (St. Jude MedicalInc., MN, USA), Acurate Vavle, (Symetis, Ecublens, VD, Switzerland),Engager valve (Medtronic, Inc., USA), and the JenaClip (JenaValve, Inc.,Munich Germany). In addition, the following U.S. Patents andPublications describe valves suitable for use with devices of theinvention: U.S. Pat. Nos. 8,500,798; 8,454,685; 8,353,954; 8,454,686;8,597,349; 8,349,000; 2013/0338766; 2013/0053949; and 2013/0218267.

In certain embodiments, in addition to a filter or a valve, the deliverydevices of the invention may also be used to insert one or more sensorswithin the vessel. Preferably, the sensors are biodegradable. Thesensors may be separate from the filter or the valve or a part of thefilter or the valve. Suitable sensors include pressure sensors, flowsensors, pH sensors, temperature sensors, etc.

Catheter bodies intended for intravascular introduction (such as theelongate body, inner member, inner sheath, and outer sheath) of thedelivery device, will typically have a length in the range from 50 cm to200 cm and an outer diameter in the range from 1 French to 12 French(0.33 mm: 1 French), usually from 3 French to 9 French. In the case ofcoronary catheters, the length is typically in the range from 125 cm to200 cm, the diameter is preferably below 8 French, more preferably below7 French, and most preferably in the range from 2 French to 7 French.Catheter bodies will typically be composed of an organic polymer that isfabricated by conventional extrusion techniques. Suitable polymersinclude polyvinylchloride, polyurethanes, polyesters,polytetrafluoroethylenes (PTFE), silicone rubbers, natural rubbers, andthe like. Optionally, the catheter body may be reinforced with braid,helical wires, coils, axial filaments, or the like, in order to increaserotational strength, column strength, toughness, pushability, and thelike. Suitable catheter bodies may be formed by extrusion, with one ormore channels being provided when desired. The catheter diameter can bemodified by heat expansion and shrinkage using conventional techniques.The resulting catheters will thus be suitable for introduction to thevascular system, often the coronary arteries, by conventionaltechniques.

The distal portion of the catheters of the present invention may have awide variety of forms and structures. In many embodiments, a distalportion of the catheter is more rigid than a proximal portion, but inother embodiments the distal portion may be equally as flexible as theproximal portion. One aspect of the present invention provides cathetershaving a distal portion with a reduced rigid length. The reduced rigidlength can allow the catheters to access and treat tortuous vessels andsmall diameter body lumens. In most embodiments a rigid distal portionor housing of the catheter body will have a diameter that generallymatches the proximal portion of the catheter body, however, in otherembodiments, the distal portion may be larger or smaller than theflexible portion of the catheter.

A rigid distal portion of a catheter body can be formed from materialsthat are rigid or which have very low flexibilities, such as metals,hard plastics, composite materials, NiTi, steel with a coating such astitanium nitride, tantalum, ME-92 (antibacterial coating material),diamonds, or the like. Most usually, the distal end of the catheter bodywill be formed from stainless steel or platinum/iridium. The length ofthe rigid distal portion may vary widely, typically being in the rangefrom 5 mm to 35 mm, more usually from 10 mm to 25 mm, and preferablybetween 6 mm and 8 mm. In contrast, conventional catheters typicallyhave rigid lengths of approximately 16 mm. The opening 1001 of thepresent invention will typically have a length of approximately 2 mm. Inother embodiments, however, the opening can be larger or smaller.

The inner member (i.e. push rod or sheath) disposed within the deliverysystem can include any suitable material having a shaft with enoughrigidity to deploy an implant while being flexible enough to movethrough a body lumen. Like the catheter, the inner member can be formedfrom polymers optionally reinforced with braid, helical wires, coils,axial filaments, or the like, in order to increase rotational strength,column strength, toughness, pushability, and the like. Suitable polymersinclude polyvinylchloride, polyurethanes, polyesters,polytetrafluoroethylenes (PTFE), silicone rubbers, natural rubbers, andthe like.

According to certain embodiments, the delivery device includes one ormore imaging elements. In certain aspects, the elongate body of thedelivery device includes an imaging element and the inner member of thedelivery device includes an imaging element. The imaging element of theelongate body and the imaging element of the inner member may be thesame or different. Imaging elements suitable for use with the deliverydevices of the invention are described hereinafter. The imaging elementis a component of an imaging assembly. Any imaging assembly may be usedwith devices and methods of the invention, such as optical-acousticimaging apparatus, intravascular ultrasound (IVUS) or optical coherencetomography (OCT). The imaging element is used to send and receivesignals to and from the imaging surface that form the imaging data.

The imaging assembly may be an intravascular ultrasound (IVUS) imagingassembly. IVUS uses an ultrasound probe attached at the distal end. Theultrasound probe can either be either a rotating transducer or an arrayof circumferentially positioned transducers. For example and as shown inthroughout the figures (e.g. FIG. 3), the ultrasound probe can be theimaging element 10 on the elongate body 25 and/or imaging element 90 onthe inner member 70. The proximal end of the catheter is attached tocomputerized ultrasound equipment. The IVUS imaging element (i.e.ultrasound probe) includes transducers that image the tissue withultrasound energy (e.g., 20-50 MHz range) and image collectors thatcollect the returned energy (echo) to create an intravascular image. Theimaging transducers and imaging collectors are coupled to signal linesthat run through the length of the catheter and couple to thecomputerized ultrasound equipment. For example, the signal lines 65 and80 coupled to the imaging elements or sensors shown throughout theFigures, including in FIG. 3.

IVUS imaging assemblies produce ultrasound energy and receive echoesfrom which real time ultrasound images of a thin section of the bloodvessel are produced. The imaging transducers of the imaging element areconstructed from piezoelectric components that produce sound energy at20-50 MHz. The image collectors of the imaging element comprise separatepiezoelectric elements that receive the ultrasound energy that isreflected from the vasculature. Alternative embodiments of imagingassembly may use the same piezoelectric components to produce andreceive the ultrasonic energy, for example, by using pulsed ultrasound.That is, the imaging transducer and the imaging collectors are the same.Another alternative embodiment may incorporate ultrasound absorbingmaterials and ultrasound lenses to increase signal to noise.

IVUS data is typically gathered in segments where each segmentrepresents an angular portion of an IVUS image. Thus, it takes aplurality of segments (or a set of IVUS data) to image an entirecross-section of a vascular object. Furthermore, multiple sets of IVUSdata are typically gathered from multiple locations within a vascularobject (e.g., by moving the transducer linearly through the vessel).These multiple sets of data can then be used to create a plurality oftwo-dimensional (2D) images or one three-dimensional (3D) image.

IVUS imaging assemblies and processing of IVUS data are described infurther detail in, for example, Yock, U.S. Pat. Nos. 4,794,931,5,000,185, and 5,313,949; Sieben et al., U.S. Pat. Nos. 5,243,988, and5,353,798; Crowley et al., U.S. Pat. No. 4,951,677; Pomeranz, U.S. Pat.No. 5,095,911, Griffith et al., U.S. Pat. No. 4,841,977, Maroney et al.,U.S. Pat. No. 5,373,849, Born et al., U.S. Pat. No. 5,176,141, Lancee etal., U.S. Pat. No. 5,240,003, Lancee et al., U.S. Pat. No. 5,375,602,Gardineer et al., U.S. Pat. No. 5,373,845, Seward et al., Mayo ClinicProceedings 71(7):629-635 (1996), Packer et al., Cardiostim Conference833 (1994), “Ultrasound Cardioscopy,” Eur. J.C.P.E. 4(2):193 (June1994), Eberle et al., U.S. Pat. No. 5,453,575, Eberle et al., U.S. Pat.No. 5,368,037, Eberle et at., U.S. Pat. No. 5,183,048, Eberle et al.,U.S. Pat. No. 5,167,233, Eberle et at., U.S. Pat. No. 4,917,097, Eberleet at., U.S. Pat. No. 5,135,486, U.S. Pub. 2009/0284332; U.S. Pub.2009/0195514 A1; U.S. Pub. 2007/0232933; and U.S. Pub. 2005/0249391 andother references well known in the art relating to intraluminalultrasound devices and modalities.

In other embodiments, the imaging assembly may be an optical coherencetomography imaging assembly. OCT is a medical imaging methodology usinga miniaturized near infrared light-emitting probe. As an optical signalacquisition and processing method, it captures micrometer-resolution,three-dimensional images from within optical scattering media (e.g.,biological tissue). Recently it has also begun to be used ininterventional cardiology to help diagnose coronary artery disease. OCTallows the application of interferometric technology to see from inside,for example, blood vessels, visualizing the endothelium (inner wall) ofblood vessels in living individuals.

OCT systems and methods are generally described in Castella et al., U.S.Pat. No. 8,108,030, Milner et al., U.S. Patent Application PublicationNo. 2011/0152771, Condit et al., U.S. Patent Application Publication No.2010/0220334, Castella et al., U.S. Patent Application Publication No.2009/0043191, Milner et al., U.S. Patent Application Publication No.2008/0291463, and Kemp, N., U.S. Patent Application Publication No.2008/0180683, the content of each of which is incorporated by referencein its entirety.

In OCT, a light source delivers a beam of light to an imaging device toimage target tissue. Light sources can include pulsating light sourcesor lasers, continuous wave light sources or lasers, tunable lasers,broadband light source, or multiple tunable laser. Within the lightsource is an optical amplifier and a tunable filter that allows a userto select a wavelength of light to be amplified. Wavelengths commonlyused in medical applications include near-infrared light, for examplebetween about 800 nm and about 1700 nm.

Aspects of the invention may obtain imaging data from an OCT system,including OCT systems that operate in either the time domain orfrequency (high definition) domain. Basic differences betweentime-domain OCT and frequency-domain OCT is that in time-domain OCT, thescanning mechanism is a movable mirror, which is scanned as a functionof time during the image acquisition. However, in the frequency-domainOCT, there are no moving parts and the image is scanned as a function offrequency or wavelength.

In time-domain OCT systems an interference spectrum is obtained bymoving the scanning mechanism, such as a reference mirror,longitudinally to change the reference path and match multiple opticalpaths due to reflections within the sample. The signal giving thereflectivity is sampled over time, and light traveling at a specificdistance creates interference in the detector. Moving the scanningmechanism laterally (or rotationally) across the sample producestwo-dimensional and three-dimensional images.

In frequency domain OCT, a light source capable of emitting a range ofoptical frequencies excites an interferometer, the interferometercombines the light returned from a sample with a reference beam of lightfrom the same source, and the intensity of the combined light isrecorded as a function of optical frequency to form an interferencespectrum. A Fourier transform of the interference spectrum provides thereflectance distribution along the depth within the sample.

Several methods of frequency domain OCT are described in the literature.In spectral-domain OCT (SD-OCT), also sometimes called “Spectral Radar”(Optics letters, Vol. 21, No. 14 (1996) 1087-1089), a grating or prismor other means is used to disperse the output of the interferometer intoits optical frequency components. The intensities of these separatedcomponents are measured using an array of optical detectors, eachdetector receiving an optical frequency or a fractional range of opticalfrequencies. The set of measurements from these optical detectors formsan interference spectrum (Smith, L. M. and C. C. Dobson, Applied Optics28: 3339-3342), wherein the distance to a scatterer is determined by thewavelength dependent fringe spacing within the power spectrum. SD-OCThas enabled the determination of distance and scattering intensity ofmultiple scatters lying along the illumination axis by analyzing asingle the exposure of an array of optical detectors so that no scanningin depth is necessary. Typically the light source emits a broad range ofoptical frequencies simultaneously.

Alternatively, in swept-source OCT, the interference spectrum isrecorded by using a source with adjustable optical frequency, with theoptical frequency of the source swept through a range of opticalfrequencies, and recording the interfered light intensity as a functionof time during the sweep. An example of swept-source OCT is described inU.S. Pat. No. 5,321,501.

Generally, time domain systems and frequency domain systems can furthervary in type based upon the optical layout of the systems: common beampath systems and differential beam path systems. A common beam pathsystem sends all produced light through a single optical fiber togenerate a reference signal and a sample signal whereas a differentialbeam path system splits the produced light such that a portion of thelight is directed to the sample and the other portion is directed to areference surface. Common beam path systems are described in U.S. Pat.Nos. 7,999,938; 7,995,210; and 7,787,127 and differential beam pathsystems are described in U.S. Pat. Nos. 7,783,337; 6,134,003; and6,421,164, the contents of each of which are incorporated by referenceherein in its entirety.

In yet another embodiment, the imaging assembly is an optical-acousticimaging apparatus. Optical-acoustic imaging apparatus include at leastone imaging element to send and receive imaging signals. In oneembodiment, the imaging element includes at least oneacoustic-to-optical transducer. In certain embodiments, theacoustic-to-optical transducer is an Fiber Bragg Grating within anoptical fiber. In addition, the imaging elements may include the opticalfiber with one or more Fiber Bragg Gratings (acoustic-to-opticaltransducer) and one or more other transducers. The at least one othertransducer may be used to generate the acoustic energy for imaging.Acoustic generating transducers can be electric-to-acoustic transducersor optical-to-acoustic transducers. The imaging elements suitable foruse in devices of the invention are described in more detail below.

Fiber Bragg Gratings for imaging provides a means for measuring theinterference between two paths taken by an optical beam. Apartially-reflecting Fiber Bragg Grating is used to split the incidentbeam of light into two parts, in which one part of the beam travelsalong a path that is kept constant (constant path) and another parttravels a path for detecting a change (change path). The paths are thencombined to detect any interferences in the beam. If the paths areidentical, then the two paths combine to form the original beam. If thepaths are different, then the two parts will add or subtract from eachother and form an interference. The Fiber Bragg Grating elements arethus able to sense a change wavelength between the constant path and thechange path based on received ultrasound or acoustic energy. Thedetected optical signal interferences can be used to generate an imageusing any conventional means.

Exemplary optical-acoustic imaging assemblies are disclosed in moredetail in U.S. Pat. Nos. 6,659,957 and 7,527,594, 7,245,789, 7447,388,7,660,492, 8,059,923 and in U.S. Patent Publication Nos. 2008/0119739,2010/0087732 and 2012/0108943.

According to certain embodiments, devices of the invention include oneor more sensors to obtain functional flow measurements within thevessel. The functional flow data can be used to assess whether bloodflow through a vessel or a valve is normal. This can then be used todetermine whether an interventional procedure is necessary (e.g.introduction of an implant to restore normal blood flow) and/or toverify success of an implant deployed by devices of the invention (e.g.whether an implant restored normal blood flow).

The functional flow data obtained by the one or more sensors may be usedto assist in locating a implantation site and to assess the restorationof blood flow after introduction of an implant such as a filter orvalve. In such embodiments, the one or more sensors may include apressure sensor, a flow sensor, and combinations thereof. The pressuresensor and the flow sensor may be fiber optic based. Pressure sensorscan be used to measure pressure within a lumen and flow sensors can beused to measure the velocity of blood flow through a lumen. Devices withboth a pressure sensor and a flow sensor provides information and datafor calculating fractional flow reserve (FFR) using pressure readings,and coronary flow reserve (CFR), or similar, using flow readings.

The ability to measure and compare both the pressure and velocity flowto determine an index of resistance of flow within the vessel allows oneto determine an ideal placement for an implant. It has been shown thatdistal pressure and velocity measurements, particularly regarding thepressure drop-velocity relationship such as Fractional Flow reserve(FFR). Coronary flow reserve (CFR) and combined P-V curves, revealinformation about the health of the vessel and its need for aninterventional procedure to restore normal functional flow parameters.

A pressure sensor allows one to obtain pressure measurements within abody lumen. A particular benefit of pressure sensors is that pressuresensors allow one to measure of FFR in vessel. FFR is a comparison ofthe pressure within a vessel at a proximal position and a distalposition. The FFR value allows one to assess pressure before and aftervascular access creation to determine the impact of the procedure. Apressure sensor can be mounted on the distal portion of delivery device100 (e.g. FIGS. 1-3 or FIGS. 14A-14C), and can be placed distal orproximal to the imaging sensor. In certain embodiments, the pressuresensor can be embedded within the imaging sensor. The pressure sensorcan be formed of a crystal semiconductor material having a recesstherein and forming a diaphragm bordered by a rim. A reinforcing memberis bonded to the crystal and reinforces the rim of the crystal and has acavity therein underlying the diaphragm and exposed to the diaphragm. Aresistor having opposite ends is carried by the crystal and has aportion thereof overlying a portion of the diaphragm. Electricalconductor wires can be connected to opposite ends of the resistor andextend within the elongate body 25 or outer sheath 1103 to the proximalportion where they connect with the operating system. Additional detailsof suitable pressure sensors that may be used with devices of theinvention are described in U.S. Pat. No. 6,106,476. U.S. Pat. No.6,106,476 also describes suitable methods for mounting the pressuresensor 104 within a sensor housing.

In certain aspects, devices of the invention include a flow sensor. Theflow sensor can be used to measure blood flow velocity within thevessel, which can be used to assess coronary flow reserve (CFR), orsimilar. The flow sensor can be, for example, an ultrasound transducer,a Doppler flow sensor or any other suitable flow sensor, disposed at orin close proximity to the distal end of the elongate body 25 or outersheath 1102, and can be proximal or distal to the imaging element 10. Incertain embodiments, the flow sensor is embedded within the imagingelement 10. The ultrasound transducer may be any suitable transducer,and may be mounted in the distal end using any conventional method,including the manner described in U.S. Pat. Nos. 5,125,137, 6,551,250and 5,873,835.

In some embodiments, a device of the invention includes an imaging andsensor assembly and obtain datasets through the operation of OCT, IVUS,or other imaging hardware associated with the imaging element as well asthe functional flow hardware associated with the one or more sensors. Insome embodiments, a device of the invention is a computer device such asa laptop, desktop, or tablet computer, and obtains a three-dimensionaldata set by retrieving it from a tangible storage medium, such as a diskdrive on a server using a network or as an email attachment.

Methods of the invention can be performed using software, hardware,firmware, hardwiring, or combinations of any of these. Featuresimplementing functions can also be physically located at variouspositions, including being distributed such that portions of functionsare implemented at different physical locations (e.g., imaging apparatusin one room and host workstation in another, or in separate buildings,for example, with wireless or wired connections).

In some embodiments, a user interacts with a visual interface to viewimages from the imaging system and functional flow data from the one ormore sensors. Input from a user (e.g., parameters or a selection) arereceived by a processor in an electronic device. The selection can berendered into a visible display. An exemplary system including anelectronic device is illustrated in FIG. 13. As shown in FIG. 13, animaging/sensor engine 859 of the imaging and sensor assembliescommunicates with host workstation 433 as well as optionally server 413over network 409. The data acquisition element 855 (DAQ) of the imagingengine receives imaging data from one or more imaging element. In someembodiments, an operator uses computer 449 or terminal 467 to controlsystem 400 or to receive images and functional flow data. Image andfunctional flow data may be displayed using an I/O 454, 437, or 471,which may include a monitor. Any I/O may include a keyboard, mouse ortouchscreen to communicate with any of processor 421, 459, 441, or 475,for example, to cause data to be stored in any tangible, nontransitorymemory 463, 445, 479, or 429. Server 413 generally includes an interfacemodule 425 to effectuate communication over network 409 or write data todata file 417.

Processors suitable for the execution of computer program include, byway of example, both general and special purpose microprocessors, andany one or more processor of any kind of digital computer. Generally, aprocessor will receive instructions and data from a read-only memory ora random access memory or both. The essential elements of computer are aprocessor for executing instructions and one or more memory devices forstoring instructions and data. Generally, a computer will also include,or be operatively coupled to receive data from or transfer data to, orboth, one or more mass storage devices for storing data, e.g., magnetic,magneto-optical disks, or optical disks. Information carriers suitablefor embodying computer program instructions and data include all formsof non-volatile memory, including by way of example semiconductor memorydevices, (e.g., EPROM, EEPROM, solid state drive (SSD), and flash memorydevices); magnetic disks, (e.g., internal hard disks or removabledisks); magneto-optical disks; and optical disks (e.g., CD and DVDdisks). The processor and the memory can be supplemented by, orincorporated in, special purpose logic circuitry.

To provide for interaction with a user, the subject matter describedherein can be implemented on a computer having an I/O device, e.g., aCRT, LCD, LED, or projection device for displaying information to theuser and an input or output device such as a keyboard and a pointingdevice, (e.g., a mouse or a trackball), by which the user can provideinput to the computer. Other kinds of devices can be used to provide forinteraction with a user as well. For example, feedback provided to theuser can be any form of sensory feedback, (e.g., visual feedback,auditory feedback, or tactile feedback), and input from the user can bereceived in any form, including acoustic, speech, or tactile input.

The subject matter described herein can be implemented in a computingsystem that includes a back-end component (e.g., a data server 413), amiddleware component (e.g., an application server), or a front-endcomponent (e.g., a client computer 449 having a graphical user interface454 or a web browser through which a user can interact with animplementation of the subject matter described herein), or anycombination of such back-end, middleware, and front-end components. Thecomponents of the system can be interconnected through network 409 byany form or medium of digital data communication, e.g., a communicationnetwork. Examples of communication networks include cell network (e.g.,3G or 4G), a local area network (LAN), and a wide area network (WAN),e.g., the Internet.

The subject matter described herein can be implemented as one or morecomputer program products, such as one or more computer programstangibly embodied in an information carrier (e.g., in a non-transitorycomputer-readable medium) for execution by, or to control the operationof, data processing apparatus (e.g., a programmable processor, acomputer, or multiple computers). A computer program (also known as aprogram, software, software application, app, macro, or code) can bewritten in any form of programming language, including compiled orinterpreted languages (e.g., C, C++, Perl), and it can be deployed inany form, including as a stand-alone program or as a module, component,subroutine, or other unit suitable for use in a computing environment.Systems and methods of the invention can include instructions written inany suitable programming language known in the art, including, withoutlimitation, C, C++, Perl, Java, ActiveX, HTML5, Visual Basic, orJavaScript.

A computer program does not necessarily correspond to a file. A programcan be stored in a portion of file 417 that holds other programs ordata, in a single file dedicated to the program in question, or inmultiple coordinated files (e.g., files that store one or more modules,sub-programs, or portions of code). A computer program can be deployedto be executed on one computer or on multiple computers at one site ordistributed across multiple sites and interconnected by a communicationnetwork.

A file can be a digital file, for example, stored on a hard drive, SSD,CD, or other tangible, non-transitory medium. A file can be sent fromone device to another over network 409 (e.g., as packets being sent froma server to a client, for example, through a Network Interface Card,modem, wireless card, or similar).

Writing a file according to the invention involves transforming atangible, non-transitory computer-readable medium, for example, byadding, removing, or rearranging particles (e.g., with a net charge ordipole moment into patterns of magnetization by read/write heads), thepatterns then representing new collocations of information aboutobjective physical phenomena desired by, and useful to, the user. Insome embodiments, writing involves a physical transformation of materialin tangible, non-transitory computer readable media (e.g., with certainoptical properties so that optical read/write devices can then read thenew and useful collocation of information, e.g., burning a CD-ROM). Insome embodiments, writing a file includes transforming a physical flashmemory apparatus such as NAND flash memory device and storinginformation by transforming physical elements in an array of memorycells made from floating-gate transistors. Methods of writing a file arewell-known in the art and, for example, can be invoked manually orautomatically by a program or by a save command from software or a writecommand from a programming language.

INCORPORATION BY REFERENCE

References and citations to other documents, such as patents, patentapplications, patent publications, journals, books, papers, webcontents, have been made throughout this disclosure. All such documentsare hereby incorporated herein by reference in their entirety for allpurposes.

EQUIVALENTS

The invention may be embodied in other specific forms without departingfrom the spirit or essential characteristics thereof. The foregoingembodiments are therefore to be considered in all respects illustrativerather than limiting on the invention described herein. Scope of theinvention is thus indicated by the appended claims rather than by theforegoing description, and all changes which come within the meaning andrange of equivalency of the claims are therefore intended to be embracedtherein.

What is claimed is:
 1. A device for delivering an implant into avasculature, the device comprising: an outer sheath defining a centerlumen that leads to a distal opening, the outer sheath comprising anouter imaging element configured to at least partially surround thecenter lumen such that an implant initially stored within the centerlumen is deployable through the outer imaging element; and an innersheath initially disposed within the center lumen of the outer sheathproximal to the implant, wherein the inner sheath comprises a distalportion having a push member and an inner imaging element disposedproximal of the push member, wherein the push member is configured toengage a proximal portion of the implant, wherein the inner imagingelement is initially proximal to the outer imaging element prior todeployment of the implant, wherein the implant is deployable throughmovement of one of the sheaths relative to the other one of the sheathsso that at least a portion of the inner sheath including the innerimaging element passes through the distal opening of the outer sheath,wherein during deployment of the implant into the vasculature, the innerimaging element is distal to the outer imaging element and proximate toat least a portion of the implant, thereby allowing the inner imagingelement to image the proximal portion of the implant during deployment.2. The device of claim 1, wherein the outer sheath comprises one or moresensors operable to obtain functional flow measurements that are locatedon a distal portion of the outer sheath.
 3. The device of claim 1,wherein the outer sheath comprises one or more sensors selected from thegroup consisting of a pressure sensor, a flow sensor, and a combinationthereof.
 4. The device of claim 1, wherein the outer sheath furthercomprises one or more radiopaque markers located along a length of theouter sheath.
 5. The device of claim 1, wherein the outer imagingelement comprises an ultrasound transducer.
 6. The device of claim 1,wherein proximal translation of the outer sheath relative to the innersheath deploys the implant.
 7. The device of claim 1, wherein distaltranslation of the inner sheath relative to the outer sheath deploys theimplant.
 8. The device of claim 1, wherein the implant is selected fromthe group consisting of a filter, a valve, and a stent.
 9. The device ofclaim 1 wherein the implant comprises a filter having a plurality offilter legs that, when deployed, form a funnel-like cavity in thevasculature, and wherein the inner sheath is deployed into thefunnel-like cavity so that the inner imaging element provides real-timeimages of the deployed filter legs engaged with the vasculature.
 10. Amethod for delivering an implant into a vasculature, the methodcomprising: introducing a delivery catheter into a body lumen, whereinthe delivery catheter comprises: an outer sheath defining a center lumenleading to a distal opening and comprising an outer imaging elementconfigured to at least partially surround the center lumen of the outersheath, wherein the implant is initially stored within the center lumenof the outer sheath; and an inner sheath disposed within the centerlumen proximal to the implant, wherein the inner sheath comprises adistal portion having a push member and an inner imaging element that isinitially proximal to the outer imaging element prior to deployment ofthe implant, wherein the push member is configured to engage a proximalportion of the implant; imaging a surface of a body lumen with the outerimaging element to locate an implantation site; positioning a distal endof the outer sheath at the implantation site for deployment of theimplant based on the imaging step; deploying the implant by moving oneof the sheaths relative to the other one of the sheaths so that at leasta portion of the inner sheath including the inner imaging elementextends through the distal opening of the outer sheath and into the bodylumen, thereby placing the inner imaging element in a deployed positionthat is distal to the outer imaging element; and during deployment ofthe implant, imaging the deployed implant in the body lumen with theinner imaging element while the inner imaging element is distal to theouter imaging element and proximate to at least a portion of theimplant.
 11. The method of claim 10, wherein a distal portion of theouter sheath comprises one or more sensors.
 12. The method of claim 11,wherein the one or more sensors are selected from the group consistingof a pressure sensor, a flow sensor, and a combination thereof.
 13. Themethod of claim 10, wherein the outer sheath further comprises one ormore radiopaque markers located along a length of the outer sheath. 14.The method of claim 10, wherein the inner and outer imaging elementseach comprise an ultrasound transducer.
 15. The method of claim 10,wherein proximal translation of the outer sheath relative to the innersheath deploys the implant.
 16. The method of claim 10, wherein distaltranslation of the inner sheath relative to the outer sheath deploys theimplant.
 17. The method of claim 10, wherein the implant is selectedfrom the group consisting of a filter, a valve, and a stent.
 18. Themethod of claim 10, wherein the implant comprises a filter having aplurality of filter legs that, when deployed, form a funnel-like cavityin the vasculature, and wherein the moving comprises deploying the innersheath into the funnel-like cavity so that the inner imaging elementprovides real-time images of the deployed filter legs engaged with thevasculature.
 19. The method of claim 11, further comprising measuringone or more functional flow parameters with the one or more sensors toassess health of the body lumen prior to implantation.
 20. The method ofclaim 11, further comprising measuring one or more functional flowparameters with the one or more sensors to assess function of theimplant after implantation.